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Peterbilt 357/378 Parts

Find the best Peterbilt 378 aftermarket parts in the business here at 4 State. The Peterbilt 378 semi truck represents all of the characteristics of the Peterbilt brand, and was a popular model with similar features to the Peterbilt 379. Pete truck models are a brand of choice for experienced truckers who need dependable semi trucks. 4 State Trucks has all the semi truck parts and accessories you need to make your Pete 378 stand out to showcase your unique personality. Whether you need aftermarket bumpers, exhaust, or fuel tanks, we've got you covered. Hit the open road in style and comfort with the best custom gear for your Peterbilt heavy duty truck or 18 wheeler.
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  • Qty in Cart
  • Quantity
  • Price
  • Subtotal
  • BESTfit Six Bolt Power Take-Off For Mechanical Transmissions Replaces 442XRAHXA3XD, 442XRAHXA3XD

    BESTfit Six Bolt Power Take-Off For Mechanical Transmissions Replaces 442XRAHXA3XD, 442XRAHXA3XD

    BESTFIT TRUCK PARTS

    $1,321.99
    Six Bolt Power Take-Off By BESTfit Replaces 442XRAHXA3XD, 442XRAHXA3XD Fits Mechanical TransmissionsMade for strength and reliability, the BESTfit Six Bolt Power Take-Off is a premium replacement for...
    29-07050046
    SKU:
    29-07050046
    Product Type:
    Engine Parts
    Make:
    Universal Items
    $1,321.99
    Qty in Cart: 0
    Price:
    $1,321.99
    Subtotal:
  • BESTfit Geared Adapter Power Take-Off Replaces 645GAHX3XX

    BESTfit Geared Adapter Power Take-Off Replaces 645GAHX3XX

    BESTFIT TRUCK PARTS

    $836.99
    Geared Adapter Power Take-Off By BESTfit Replaces 645GAHX3XXBuilt for strength and dependable performance, the BESTfit Geared Adapter Power Take-Off is a premium replacement for 645GAHX3XX designed...
    29-07050037
    SKU:
    29-07050037
    Product Type:
    Engine Parts
    Make:
    Universal Items
    $836.99
    Qty in Cart: 0
    Price:
    $836.99
    Subtotal:
  • BESTfit Stud Kit Replaces 707072XB, 717072X, 17072XB

    BESTfit Stud Kit Replaces 707072XB, 717072X, 17072XB

    BESTFIT TRUCK PARTS

    $32.99
    Stud Kit By BESTfit Replaces 707072XB, 717072X, 17072XBEnsure a strong and reliable PTO installation with the BESTfit Stud Kit, a premium replacement for 707072XB, 717072X, and 17072XB designed...
    29-07050042
    SKU:
    29-07050042
    Position:
    Kit Full
    Product Type:
    Engine Parts
    Make:
    Universal Items
    $32.99
    Qty in Cart: 0
    Price:
    $32.99
    Subtotal:
  • BESTfit Stud Kit Replaces 328170217X, 328170217XB

    BESTfit Stud Kit Replaces 328170217X, 328170217XB

    BESTFIT TRUCK PARTS

    $272.99
    Stud Kit By BESTfit Replaces 328170217X, 328170217XBEnsure a strong and reliable PTO installation with the BESTfit Stud Kit, a premium replacement for 328170217X and 328170217XB designed specifically...
    29-07050035
    SKU:
    29-07050035
    Product Type:
    Engine Parts
    Make:
    Universal Items
    $272.99
    Qty in Cart: 0
    Price:
    $272.99
    Subtotal:
  • BESTfit Stud Kit Replaces 32817076X, 32817076XB, 71702X

    BESTfit Stud Kit Replaces 32817076X, 32817076XB, 71702X

    BESTFIT TRUCK PARTS

    $22.99
    Stud Kit By BESTfit Replaces 32817076X, 32817076XB, 71702XEnsure a strong and reliable PTO installation with the BESTfit Stud Kit, a premium replacement for 32817076X, 32817076XB, and 71702X designed...
    29-07050033
    SKU:
    29-07050033
    Position:
    Kit Full
    Product Type:
    Engine Parts
    Make:
    Universal Items
    $22.99
    Qty in Cart: 0
    Price:
    $22.99
    Subtotal:
  • BESTfit Power Take-Off For Mechanical Transmissions Replaces 489XRAHXV3RA, 489XRAHXV3XQ, 489XRAHXV3RK

    BESTfit Power Take-Off For Mechanical Transmissions Replaces 489XRAHXV3RA, 489XRAHXV3XQ, 489XRAHXV3RK

    BESTFIT TRUCK PARTS

    $1,401.99
    Power Take-Off By BESTfit Replaces 489XRAHXV3RA, 489XRAHXV3XQ, 489XRAHXV3RK Fits Mechanical TransmissionBuilt for strength and reliability, the BESTfit Power Take-Off is a premium replacement for...
    29-07050038
    SKU:
    29-07050038
    Product Type:
    Engine Parts
    Make:
    Universal Items
    $1,401.99
    Qty in Cart: 0
    Price:
    $1,401.99
    Subtotal:
  • BESTfit Power Take-Off For Mechanical Transmissions Replaces 489XLAHXV3RK, 489XLAHXV3RA, 489XLAHXV3RB

    BESTfit Power Take-Off For Mechanical Transmissions Replaces 489XLAHXV3RK, 489XLAHXV3RA, 489XLAHXV3RB

    BESTFIT TRUCK PARTS

    $1,401.99
    Power Take-Off By BESTfit Replaces 489XLAHXV3RK, 489XLAHXV3RA, 489XLAHXV3RB Fits Mechanical TransmissionsBuilt for strength and dependable performance, the BESTfit Power Take-Off is a high-quality...
    29-07050031
    SKU:
    29-07050031
    Product Type:
    Engine Parts
    Make:
    Universal Items
    $1,401.99
    Qty in Cart: 0
    Price:
    $1,401.99
    Subtotal:
  • BESTfit Cummins DEF Doser Injector Replaces 5506855, A050S599, 4377650 For Cummins

    BESTfit Cummins DEF Doser Injector Replaces 5506855, A050S599, 4377650 For Cummins

    BESTFIT TRUCK PARTS

    $715.99
    Diesel Exhaust Fluid Doser Injector By BESTfit Replaces 5506855, A050S599, 4377650 Fits CumminsMaintain peak emissions system performance with the BESTfit Cummins DEF Doser Injector, a reliable...
    29-06070040
    SKU:
    29-06070040
    Product Type:
    Fuel Tanks
    Style Options:
    Cummins
    Make:
    Universal Items
    $715.99
    Qty in Cart: 0
    Price:
    $715.99
    Subtotal:
  • BESTfit Power Take-Off For Mechanical Transmissions Replaces 489XFAHXV3RA, 489XFAHXV3RB, 489XFAHXV3XK

    BESTfit Power Take-Off For Mechanical Transmissions Replaces 489XFAHXV3RA, 489XFAHXV3RB, 489XFAHXV3XK

    BESTFIT TRUCK PARTS

    $1,401.99
    Power Take- Off By BESTfit Replaces 489XFAHXV3RA, 489XFAHXV3RB, 489XFAHXV3XK Fits Mechanical TransmissionsBuilt for strength and reliability, the BESTfit Power Take-Off is a high-quality replacement...
    29-07050034
    SKU:
    29-07050034
    Product Type:
    Engine Parts
    Make:
    Universal Items
    $1,401.99
    Qty in Cart: 0
    Price:
    $1,401.99
    Subtotal:
  • BESTfit Stud Kit Replaces 717086X

    BESTfit Stud Kit Replaces 717086X

    BESTFIT TRUCK PARTS

    $80.99
    Stud Kit By BESTfitEnsure a strong and reliable PTO installation with the BESTfit Stud Kit, a premium replacement for 717086X designed specifically for Chelsea 280 Series PTO applications. This...
    29-07050030
    SKU:
    29-07050030
    Position:
    Kit Full
    Product Type:
    Engine Parts
    Make:
    Universal Items
    $80.99
    Qty in Cart: 0
    Price:
    $80.99
    Subtotal:
  • BESTfit DEF Sensor Head Assembly Replaces 5932338, AP65153, T434814

    BESTfit DEF Sensor Head Assembly Replaces 5932338, AP65153, T434814

    BESTFIT TRUCK PARTS

    $914.99
    Diesel Exhuast Fluid Sensor Head Assembly By BESTfit Replaces 5932338, AP65153, T434814Maintain DEF system reliability with the BESTfit DEF Sensor Head Assembly. Designed for accurate monitoring of...
    29-06070037
    SKU:
    29-06070037
    Height Options:
    13 Inch
    Product Type:
    Fuel Tanks
    Make:
    Universal Items
    $914.99
    Qty in Cart: 0
    Price:
    $914.99
    Subtotal:
  • BESTfit DEF Sensor Head Assembly Replaces 231064, 5066895, 85A7476

    BESTfit DEF Sensor Head Assembly Replaces 231064, 5066895, 85A7476

    BESTFIT TRUCK PARTS

    $1,778.99
    Diesel Exhaust Fluid Sensor Head Assembly By BESTfit Replaces 231064, 5066895, 85A7476Maintain precise emissions system performance with the BESTfit DEF Sensor Head Assembly, a premium replacement...
    29-06070039
    SKU:
    29-06070039
    Height Options:
    22 Inch
    Product Type:
    Fuel Tanks
    Make:
    Universal Items
    $1,778.99
    Qty in Cart: 0
    Price:
    $1,778.99
    Subtotal:
  • BESTfit DEF Sensor Head Assembly Replaces 2515990C3, 601965, 5511564

    BESTfit DEF Sensor Head Assembly Replaces 2515990C3, 601965, 5511564

    BESTFIT TRUCK PARTS

    $1,065.99
    Diesel Exhaust Fluid Sensor Head Assembly By BESTfit Replaces 2515990C3, 601965, 5511564Trust the BESTfit DEF Sensor Head Assembly to restore proper emissions monitoring. This high-quality component...
    29-06070033
    SKU:
    29-06070033
    Product Type:
    Fuel Tanks
    Height Options:
    11 1/2 Inch
    Make:
    Universal Items
    $1,065.99
    Qty in Cart: 0
    Price:
    $1,065.99
    Subtotal:
  • BESTfit DEF Sensor Head Assembly Replaces AP65151, 5511561, GA111561

    BESTfit DEF Sensor Head Assembly Replaces AP65151, 5511561, GA111561

    BESTFIT TRUCK PARTS

    $1,572.99
    Diesel Exhaust Fluid Sensor Head Assembly By BESTfit Replaces AP65151, 5511561, GA111561Restore accuracy to your DEF system with the BESTfit DEF Sensor Head Assembly. Engineered for CAT C4.4-style...
    29-06070035
    SKU:
    29-06070035
    Product Type:
    Fuel Tanks
    Height Options:
    22 Inch
    Make:
    Universal Items
    $1,572.99
    Qty in Cart: 0
    Price:
    $1,572.99
    Subtotal:
  • BESTfit DEF Sensor Head Assembly Replaces 3329295, 4812011099, 501740

    BESTfit DEF Sensor Head Assembly Replaces 3329295, 4812011099, 501740

    BESTFIT TRUCK PARTS

    $1,345.99
    Diesel Exhuast Fluid Sensor Head Assembly By BESTfit Replaces 3329295, 4812011099, 501740Maintain peak emissions system performance with the BESTfit DEF Sensor Head Assembly. Designed for Diesel...
    29-06070038
    SKU:
    29-06070038
    Height Options:
    18 Inch
    Product Type:
    Fuel Tanks
    Make:
    Universal Items
    $1,345.99
    Qty in Cart: 0
    Price:
    $1,345.99
    Subtotal:
  • BESTfit DEF Pump 2.2 For Cummins & Caterpillar Replaces 098644D204, 4387305, 5EL058

    BESTfit DEF Pump 2.2 For Cummins & Caterpillar Replaces 098644D204, 4387305, 5EL058

    BESTFIT TRUCK PARTS

    $1,145.99
    Diesel Exhaust Fluid Pump 2.2 By BESTfit Replaces 098644D204, 4387305, 5EL058 Fits Cummins & CaterpillarUpgrade your emissions system with the BESTfit DEF Pump 2.2, a premium replacement for part...
    29-06070024
    SKU:
    29-06070024
    Product Type:
    Exhaust
    Style Options:
    Cummins
    Make:
    Universal Items
    $1,145.99
    Qty in Cart: 0
    Price:
    $1,145.99
    Subtotal:
  • BESTfit DEF Pump 2.2 For Cummins Replaces 1819797, 2880158, A662102

    BESTfit DEF Pump 2.2 For Cummins Replaces 1819797, 2880158, A662102

    BESTFIT TRUCK PARTS

    $1,145.99
    Exhaust Fluid Pump 2.2 By BESTfit Replaces 1819797, 2880158, A662102 Fits CumminsOptimize your emissions system with the BESTfit DEF Pump 2.2, a dependable replacement for 1819797, 2880158, and...
    29-06070029
    SKU:
    29-06070029
    Product Type:
    Fuel Tanks
    Style Options:
    Cummins
    Make:
    Universal Items
    $1,145.99
    Qty in Cart: 0
    Price:
    $1,145.99
    Subtotal:
  • BESTfit DEF Sensor Head Assembly Replaces 4623219, 82196511, T434824

    BESTfit DEF Sensor Head Assembly Replaces 4623219, 82196511, T434824

    BESTFIT TRUCK PARTS

    $891.99
    Diesel Exhaust Fluid Sensor Head Assembly By BESTfitStrengthen emissions system reliability with the BESTfit DEF Sensor Head Assembly, a high-quality replacement for 4623219, 82196511, and T434824...
    29-06070031
    SKU:
    29-06070031
    Product Type:
    Fuel Tanks
    Height Options:
    11 Inch
    Make:
    Universal Items
    $891.99
    Qty in Cart: 0
    Price:
    $891.99
    Subtotal:
  • BESTfit DEF Sensor Head Assembly Replaces 82217519, 918161618, APP41422

    BESTfit DEF Sensor Head Assembly Replaces 82217519, 918161618, APP41422

    BESTFIT TRUCK PARTS

    $1,057.99
    Diesel Exhaust Fluid Sensor Head Assembly By BESTfit Replaces 82217519, 918161618, APP41422Count on accurate DEF monitoring with the BESTfit DEF Sensor Head Assembly, replacing 82217519, 918161618,...
    29-06070034
    SKU:
    29-06070034
    Height Options:
    18 Inch
    Product Type:
    Fuel Tanks
    Make:
    Universal Items
    $1,057.99
    Qty in Cart: 0
    Price:
    $1,057.99
    Subtotal:
  • BESTfit DEF Sensor Head Assembly Replaces 3600932, 5913429, 714898

    BESTfit DEF Sensor Head Assembly Replaces 3600932, 5913429, 714898

    BESTFIT TRUCK PARTS

    $887.99
    Diesel Exhaust Fluid Sensor Head Assembly By BESTfitEnsure consistent emissions performance with the BESTfit DEF Sensor Head Assembly. Built for CAT C3.6 and C4.4 engines, this assembly accurately...
    29-06070020
    SKU:
    29-06070020
    Product Type:
    Fuel Tanks
    Height Options:
    18 Inch
    Make:
    Universal Items
    $887.99
    Qty in Cart: 0
    Price:
    $887.99
    Subtotal:
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Adding your products to cart

The Peterbilt 357 and 378 are known for their no-nonsense durability and old-school style. Whether you’re hauling heavy loads or running construction jobs, these workhorses are built to last—and we’re here to help you keep them in top shape.

Why Choose Aftermarket Peterbilt 357/378 Truck Parts?

- Engineered for your model: Every part is made to fit and function with your 357 or 378—so you can skip the guesswork and get back to work. - Performance you can count on: Keep your truck running strong with engine, transmission, suspension, fiberglass Pete 357/378 hood shells, LED headlights, and cab lighting accessories designed to turn heads. - Trusted brands, proven quality: We only carry parts from manufacturers we trust, so you know you're getting durable, road-tested gear. - Quick shipping, expert help: Get your parts fast and reach out to our team if you need help finding the right fit—we’ve got your back.

Shop the Perfect Aftermarket Accessories for Peterbilt 357/378 Trucks


Whether you're restoring a classic or keeping your work truck rolling, our Peterbilt 357 and 378 parts are built to match the strength and legacy of these iconic models. We stock a wide selection of aftermarket and replacement parts designed specifically for Peterbilt 357 and 378 models. From critical mechanical components to sleek interior cab accessory upgrades, we’ve got what you need to maintain, repair, or customize your rig. Explore our full selection and get the parts you need to keep your rig road-ready.

Frequently Asked Questions About Peterbilt 357/378 Parts

What years and models are compatible with Peterbilt 357/378 parts?

Most aftermarket parts for Peterbilt 357/378 trucks are designed to fit models from 1987 through 2007. However, there are important differences between early models (1987-1999) and later models (2000-2007), particularly in hood mounting points and grille configurations. Always verify the specific year range listed for each part, as some components like bumpers and fenders may have changed mounting hole patterns after the 2000 model year update.

Are aftermarket bumpers as durable as OEM Peterbilt bumpers?

Quality aftermarket bumpers are typically made from 16-gauge steel (same as OEM) and feature triple chrome plating or powder coating for corrosion resistance. The main differences you'll find are in the finishing details and fitment precision. While a well-made aftermarket bumper can last just as long as OEM, pay attention to the warranty offered - reputable manufacturers typically provide at least a 1-year warranty on chrome finish and 3-5 years on structural integrity.

What tools and modifications are needed to install replacement parts?

Most bolt-on parts like bumpers, grilles, and headlight assemblies require basic hand tools including socket sets (typically 1/2" to 3/4"), wrenches, and a drill with metal bits for any minor adjustments. Common installation challenges include slight drilling to align mounting holes (especially on pre-2000 models) and adjusting bumper brackets for proper fitment. Professional installation typically takes 2-4 hours for major components like bumpers or hoods.

What's the difference between chrome, stainless steel, and painted finishes?

Chrome-plated steel offers the brightest mirror finish but requires regular polishing and can pit in harsh climates. Stainless steel (usually 304 grade) provides excellent corrosion resistance with less maintenance but has a slightly duller appearance. Painted finishes are the most economical and can be color-matched to your truck, but may need repainting every 5-7 years depending on exposure. For winter driOEMg or coastal areas, stainless steel typically offers the best long-term value.

How do I ensure proper fitment when ordering hoods, fenders, or bumpers?

Start by confirming your exact model year and checking whether you have a standard or extended hood configuration. Measure key mounting points on your current parts before ordering - bumper width should be either 18" or 20" depending on your model. For hoods and fenders, verify whether you have the single-headlight or dual-headlight configuration. When in doubt, provide your OEM number when ordering to ensure compatibility, as some mid-year production changes aren't reflected in standard model year listings.


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